1. Professor, School of Civil Engineering, Xuzhou Univ. of Technology, Xuzhou 221008, China (corresponding author).
2. Professor, School of Mechanics and Civil Engineering, China Univ. of Mining and Technology, Xuzhou 221008, China.
3. Research Associate, State Key Laboratory of Geomechanics and Deep Underground Engineering, China Univ. of Mining and Technology, Xuzhou 221008, China.
4. Lecturer, School of Civil Engineering, Xuzhou Univ. of Technology, Xuzhou 221008, China.